So I finally got my new 63B550 set up last night. WOW! I actually considered calling in sick today just to spend more time with it. Hooked up my comcast HD DVR. HD obviously looked terrific out of the box.
Black levels I thought were great. I was watching last night with very little ambient light and I thought they looked fantastic. Could they have been a bit darker? Yes, and Im sure if you sat a Kuro next to it and compared I'm sure I would be able to see a little bit of a difference but not nearly enough to justify spending an extra $1000+ for such a minimal gain. Note that I am coming from a Mits 52625 DLP (with terrible black levels), so pretty much anything is going to look great to me in terms of blacks.
SD I thought looked anywhere from ok to good. Not great, but certainly not poor. Certainly watchable, although I dont really plan to watch much SD anyways.
My experience with the buzzing sound goes something like this. When I was standing next to the tv I could clearly hear the buzzing. When I sat down at my normal viewing distance with the TV muted I could somewhat faintly hear the buzzing. When I was watching tv with any kind of volume at all I didnt notice a thing unless I was really trying hard to listen for it, and even then it wasnt bothersome to me at all, I could just kind of tell it was there in the background. I spent 5+ hours watching tv last night and it didnt once bother me. If I were to guess I would say its about half as loud as the fan on my old Mits 52625. Not going to be a problem for me at all!!!
IR was something that did concern me a bit going into this purchase (this is my first plasma). Im being cautious my first 200 or so hours while my TV breaks in. At one point last night I watched about 10-12 minutes of the Detroit Pitt game on VS. They had the logo and the score bar at the top of the screen. It was totally fixed on my screen between commercial breaks. I quickly turned on the scrolling bars to see if I could see some IR as the bars scrolled across the screen. When I looked hard I could very faintly see the score bar at the top. With literally one pass of the scroll bar everything totally disappeared, even from 2 feet away I couldnt see anything. I also watched 20-30 minutes of a movie with bars at the top and bottom and quickly switched away to the scrolling bars to see if I could see any hint of IR and I couldnt find any at all. Overall, I feel a lot better about the whole IR issue then I did prior to my purchase. Im still going to be careful, especially during the first 200 or so hours, but Im not really worried at all anymore.
I guess the best way to summarize how I feel after watching my new tv for 5-6 hours is that I'm very pleased that I made this purchase. So far its turned out to be everything I hoped and expected it to be.
Sorry for the crazy, quick, and poorly written summary
(I wrote this all in about 5 minutes and dont have time to proof read). Im just average person with average at best HD technical knowledge. So maybe this may help another average guy who is on the fence about this tv. Did I mention I love this TV?